Douglas Isbell
Headquarters, Washington, DC March 12, 1997
(Phone: 202/358-1547)
David Morse
Ames Research Center, Mountain View, CA
(Phone: 415/604-4724)
RELEASE: 97-38
LUNAR PROSPECTOR SPACECRAFT CONSTRUCTION COMPLETE
Construction and assembly of NASA's Lunar Prospector
spacecraft, designed to obtain the first complete compositional
and gravity maps of the Moon, has been completed in preparation
for its scheduled September 1997 launch.
Functional and environmental spacecraft tests will be
conducted over the next several months, according to project
manager Tom Dougherty of Lockheed Martin Missiles & Space,
Sunnyvale, CA. Once this activity is successfully completed,
current plans call for the spacecraft to be shipped to Spaceport
Florida in late August for launch on September 24, 1997.
"We're delighted with progress to date," said Scott Hubbard,
NASA Lunar Prospector mission manager at Ames Research Center,
Mountain View, CA. "Lockheed Martin and its construction team put
a detailed program into place and executed it well within the
established schedule and with tight cost control."
The total cost of the mission to NASA, including launch,
mission operations and data analysis, is $63 million.
Why is NASA going back to the Moon? Despite a high level of
scientific and public interest, particularly during the Apollo
era, major gaps remain in scientific knowledge about Earth's
nearest planetary neighbor, according to project scientists. Over
75 percent of the lunar surface is not mapped in detail, and
important questions about the Moon's history, composition and
internal processes remain unanswered.
During its planned one-year polar orbiting mission, Lunar
Prospector will map the Moon's surface composition, gravity and
magnetic fields, and try to detect volatile release activity.
This information should provide insights into the origin and
evolution of the Moon. Lunar Prospector also should directly
determine the existence or absence of water ice in the Moon's
polar regions, which has been suggested by analysis of indirect,
radar-based data from the Clementine mission.
As the first peer-reviewed, competitively selected mission in
NASA's "faster, better, cheaper" Discovery Program series, Lunar
Prospector is an embodiment of the Agency's new way of doing
business. With an emphasis on minimized risk, lowered costs, and
rapid turnaround time, and its prime focus on delivery of science
data, Lunar Prospector will help usher in a new era of Solar
System exploration missions.
"Lunar Prospector is serving as a pathfinder in many
different ways," said Hubbard. The mission has "already made
history in terms of management style, technical approach, cost
management and focused science. Technical insight rather than
detailed programmatic oversight was used to ensure innovation and
maximum return on investment. The Ames program office paid close
attention to the progress of the project and its schedule, cost
and science return, but provided no detailed specifications. The
Principal Investigator was given the flexibility to implement the
best available approach," he said.
The Lunar Prospector spacecraft is a small, spin-stabilized
vehicle with a fully fueled mass of 660 pounds. It is 4.5 feet
high and 4 feet in diameter, with three 8-foot booms or masts.
Solar cells mounted on its outer surface will provide more than
200 watts of power.
Five scientific instruments are mounted on the booms to
isolate them from the main structure and electronics. A neutron
spectrometer will have the capability to locate as little as one
cup of water in about a cubic yard of lunar soil (regolith). The
discovery of water ice in the lunar polar regions would mean that
water, necessary for life support and a potential source of both
oxygen and hydrogen to produce rocket propellant, could be
available for use by future lunar explorers.
A gamma-ray spectrometer will provide global maps of the
elemental composition of the surface layer of the Moon. Improved
knowledge of the concentrations of such elements as uranium,
thorium, potassium, iron, titanium, oxygen, silicon, aluminum,
magnesium and calcium will aid in understanding the composition
and evolution of the lunar crust.
An alpha particle experiment will provide information on the
level of tectonic and volcanic lunar out-gassing activity. It
will map the locations and frequency of radon gas release events
on the Moon, a body thought to be tectonically and volcanically
dead until Apollo provided evidence that it may still have some
limited activity.
A magnetometer and electron reflectometer will map local
lunar magnetic fields, known to be weak compared to the global
magnetic field of the Earth. This will help determine the origin
of such fields and may provide information on the size and
composition of the lunar core.
The Doppler gravity experiment will provide the first global
gravity map of the Moon, essential for planning follow-on robotic
and human exploration missions. It also will provide data on
density differences in the crust, internal densities and the
nature of the core.
When Lunar Prospector is launched, it will take five days to
reach the Moon, making two midcourse maneuvers, deploying booms,
and collecting calibration data via its science instruments en
route. Once the spacecraft reaches the Moon, it will be put into
a circular, 118-minute, 62-mile altitude, polar-mapping orbit to
begin its mission.
If fuel is available at the end of the one-year nominal
mission, lunar mapping may be extended at altitudes as low as 6.2
miles over areas of special interest. After the fuel needed for
orbital maintenance is depleted, the spacecraft will eventually
impact on the lunar surface.
Further information on Lunar Prospector, including still
imagery, is available on the Internet at the following URL:
http://pyroeis.arc.nasa.gov/lunar_prospector/home.html
The Lunar Prospector mission is being implemented for NASA by
Lockheed Martin, Sunnyvale, CA, with important contributions from
Los Alamos National Laboratory, the University of California-
Berkeley Space Science Laboratory, the Goddard Space Flight
Center, Greenbelt, MD, and the Jet Propulsion Laboratory,
Pasadena, CA.